Most modern books have relatively rigid covers and backs. This is true of even paperback books in which the covers are generally stiffer than the pages. Bookmarks in the form of elastic bands have evolved because the typical bookmark can slip out of a book while elastic bands remain in place. However, elastic band bookmarks have not achieved a wide degree of public acceptance even though they enable a reader to more securely mark a page of a book.
In view of the aforementioned considerations, there is a need for bookmarks employing endless elastic bands which achieve a greater degree of public acceptance.